E30 electrical issues - BMW Forum

davE30 · 12-30-2008, 11:24 PM

hi, i recently bought a 85' 325e and have been having some troubles with the electrical system. every once in a while my parking lights and fog lights will switch on and off but there always on different sides, and the lights in my cluster will go in and out, along with the mpg and engine temp meter. Also, after like 3 to 4 days of not driving it, something im not aware of seems to be draining the battery because i will hop in and try to start it and absoultly nothing happens when i turn the key. a friend said that the wiring is probobly screwed around in some way. and i recently had a wheel bearing fixed at a local BMW autosport garage and they thought the the previous owner may have had simmilar problems. they said he replaced the battery and got a new alterator. i thought this would be the best place to search for any advice or common issues with E30's that i dont know about before i spend $400 trying to find an answer from a motorsports place. this is my first post so i hope that it works right, and i hope that this post has enough info to get a reply. thanks.

witeshark · 12-30-2008, 11:26 PM

I'd say a good start would be the fuse/relay box. After that, an old school wire hunt (especially grounds) could need to follow.

marti5 · 12-31-2008, 08:02 AM

How old is the battery, they can get a duff cell even after 18 months, if for some reason it has been drained of power many times.

davE30 · 01-01-2009, 06:26 PM

the battery was replaced with one that is a different size than normal for the car, back in aug. of '07 i think.

FE390 · 10-14-2009, 03:51 PM

Any headway on this problem.

I have a slow drain I can't find in my '87. I even pulled all the fuses not pertaining to the car running and still the battery goes dead. New battery also.